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Topic: DIRECT v2.0 - Thread 2 (Read 683819 times)

Could we take all of this somewhere else? This is supposed to be discussion about DIRECT. If you have a problem with how Chris runs his site, take it up with him in a PM. This is not the time nor the place to debate this.

Well, most of what's written is to be found within these hallowed threads & posts, but the weight of the article is jaw dropping, and I anticipate a surge* of interest in the general public when they read this.

* (maybe 1%, which is alot for the USA)

I would love to know where to get images of the J-2X engine like the one in the article. Beautiful.

The Direct team should be very proud of this acheivement. Definitely an issue for collectors.

And you gotta love having nasaspaceflight.com right there in the first line, as someone else here already pointed out. I'd be interested to know how the member ticker goes up in the next 1-2 months.

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Remembering those who made the ultimate sacrifice for our rights & freedoms, and for those injured, visible or otherwise, in that fight.

However, it would take the Direct team to provide me with an exclusive run on such news, because the other key element of this site is we never run second hand content.

Am I mis-reading this? ? ? ? You really won't report this unless DIRECT gives you an exclusive and refuses to talk to the rest of the press or any other news site? ? ? ? Hard not to understand your comment as meaning exactly this. Jeez.

I can understand if you need to hear directly from the source before you publish, but to say you won't list a news item just because someone else scooped you by 10 minutes is simply petty. It's still news (and directly from the souce), it's just not an exclusive.

I need to subscribe to some other news sites, I think, to hear all the news that you refuse to publish because someone beat you to it.

Martin

PS I'm very strongly tempted to apologise for such a dismissive tone, but if you really refuse to publish news because someone beat you to it, then you're not a news site, you're just screaming "first!" out to the internet. I would love to apologise if I've misunderstood the comment that I've quoted above, or its context.

Heh. I'll try and explain it better

We cover NASA and current vehicles - we are not covering Direct's development (and no news media site is). You're seeing numerous news media taking up a feature on Direct and that's cool - we've done the same back in 2006 and we've got the forum threads (also cool). No one is "missing" anything due to the update threads.

It was intimated why we had not run another article on Direct based on (a) The latest magazine feature. Reason: not a viable news story for us to run with for the reasons given in my other post, and (b) That we might pending any big news that directly (pun intended) relates to NASA's CxP direction.

I noted (b) would be viable if we get the news off the Direct team. Reason: It is unviable as a news site to rehash something already reported by another site. Some sites do re-write previously run content (with the "according to a report in the Blah Blah news...", but not us - we break news here for the reasons given of bringing something new to the party. But we still would run something if we had an additional angle. Basically, it HAS to be fresh news. No one here wants to re-read something they already know, and rightly so.

"Exclusive run" means breaking the news, it does not mean "do not to speak to another site." They are under no obligation to come to me with a breaking development, but the point is if they did, then I would run it (which answers the orginal question).

So the bottom line is "yes" I would write a news article about Direct (I believe the intimation is I'm avoiding such content), but "no" I wouldn't write an article on news already reported, as the readership of this site expects me to give them something new in the articles.

I wouldn't be at all surprised if the Direct team came back from their undisclosed location, and offer you (Chris) a nice scoop, worthy of an article. Not to say they will, and maybe it still isn't time to break the seal on any really big one (whatever that may be), but we at least have to be grateful that much of their discussions are based here on this site, and that says something.

Edit: 'We' instead of 'you'

« Last Edit: 01/09/2009 01:02 AM by robertross »

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Remembering those who made the ultimate sacrifice for our rights & freedoms, and for those injured, visible or otherwise, in that fight.

I wouldn't be at all surprised if the Direct team came back from their undisclosed location, and offer you (Chris) a nice scoop, worthy of an article. Not to say they will, and maybe it still isn't time to break the seal on any really big one (whatever that may be), but we at least have to be grateful that much of their discussions are based here on this site, and that says something.

Just to let the DIRECT guys know, Old Town Alexandria is a great place to get a bite to eat and relax, and if internet is an issue Just go to the Air and Space Museum on the mall, they have free WI-fi (practically lived there for spring break)

I was a little disappointed in the comparison graphic PM decided to use. I wish they had used the graphic that the Direct team has used in the past, that shows the Shuttle and compares Ares and Jupiter. This more clearly shows how Ares is not truly Shuttle derived.

And from that other publication today:301051main_Space_Transportation_Association_8_Jan_09.pdf

From Griffin...

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... Constellation is also designed to support ISS but, as clearly stated from the outset, only if commercial service fails to materialize. Constellation is not focusedon or designed for maximum efficiency in LEO operations.

Hmmm.... doesn't this flatly contradict the criticism of Direct that the J-120 "overshoots" ISS requirements?

I didn't consider the article as 'agressive', that's for sure. It was tempered by various statements, almost leaving it up to the reader to draw their own conclusions. Since there were no numbers to back up either side, due most likely to limited pages and the less tech-savy public, I wonder how people would vote on such statements.

I'm thinking it will at least draw attention to shuttle retirement, re-living nostalgic memories of Apollo 11, Challenger & Columbia, and of course the cost in today's fiscal environment. But I'm betting overall it will plant the seed that maybe NASA needs a shake-up and some real hard questions answered. It may just get Direct that new study to look at all the options and a fair and unbiased comparison.

One disappointment was the lack of their website address in the article.

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Remembering those who made the ultimate sacrifice for our rights & freedoms, and for those injured, visible or otherwise, in that fight.

I also felt it tried to give both sides a chance, and was definitely left to the reader to take a position. But the overall tone was pro-Direct I feel.

The stories of people getting threatened and fired for speaking out, the engineer from ULA countering what Cooke had to say about the Jupiter upperstage. There was a slight Big Bad Government vs Innocent Small Guy feel to it.

Have the dangers of an ocean spash-down been added to the Ares-I LOC numbers? All kinds of things can go wrong with an ocean splash-down, such as the capsule capsizing or sinking, or the flotation devices could malfunction. Surely that would have an adverse affect on the safety ratings of the mission. I can't imagine that there could be 2000 splash-downs without a serious event taking place at least once.

Mark S.

To the best of my knowledge, Ares-I LOM/LOC numbers do NOT include any spacecraft recovery events or milestones. IIRC, they are limited to the spacecraft launch. Someone please correct me if that is not right.

So, the Columbia accident should not count towards Shuttle LOC numbers, in that case. Sure, the trigger event was during the launch, but they actually survived the launch, completed their science mission, and had left orbit. Clearly, that line of logic does not hold up.

I would say that LOC/LOM numbers have to account for and include any possible loss while riding in, on, or around any NASA vehicle. Once they are safely on board the Nimitz (or whatever), then NASA can be absolved of responsibility.

Didn't one of the Mercury capsules actually sink, and nearly take the astronaut down with it?

Mark S.

Being fair, there is a very big difference between Launch Vehicle LOM/LOC numbers and Mission LOM/LOC numbers. While there are certain launch events that can have an affect on the Mission numbers, as in Columbia, typically the Launch Vehicle numbers do not include Mission numbers but are considered and quoted separately. Launching the spacecraft is the job of the launch vehicle. The mission after orbital insertion is generally not affected by the launch vehicle. That's why the mission numbers are quoted separately from the launch event.

The falacy in this particular case (Orion/Ares vs. Orion/Jupiter) is the current design of Orion has been severly compromised by the performance limitations of Ares-I, making the spacecraft much less safe than it would have been otherwise. It is not UN-safe, it is LESS-safe. That does NOT include resulting spacecraft performance shortfalls, only safety considerations; things like lacking mmod protection, reduced survival time in the water after splashdown, and single fault tolerant systems vs. dual fault tolerant.

Kind of like saying foam strikes make shuttle "LESS safe"... unless of course you die because of it... I think that would tend to demonstrate the vehicle to be "UNsafe"...

No harm no foul?? Isn't that the sort of thinking that led to the Challenger and Columbia disasters, even though evidence of prior damage/failure during previous missions showed there was a problem that, in hindsight, should have been addressed, and if it had, could likely have prevented the loss of the crews involved?? I tend to think that pushes such a problem into the 'unsafe' category myself... OL JR

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NO plan IS the plan...

"His plan had no goals, no timeline, and no budgetary guidelines. Just maybe's, pretty speeches, and smokescreens."

Sure it is; it's one with side-mounted, jettisonable engines and controls.

Structurally it's a stage. Get over it and pick something else to poke at.

It's not a good idea to dismiss criticism.DIRECT will be reviewed by NASA under their own terms. NASA have designed an upper stage for the Ares-V, and it comes out at a much more conservative dry mass than JUS. Hence they will try to criticise the JUS. A 'pre-rebuttal' is needed to ensure that JUS's numbers can be verifed.

I'm not dismissing crticism, I'm addressing and refuting it. The claim is that JUS is dubious because no hardware with equivalent performance has ever flown. I believe I have demonstrated that hardware with much better performance has flown, but that data was rejected due to semantics.

A much better criticism would be to analyze the forces & material properties, then show whether or not the structure is physically capable of performing as proposed. Neither the above posters nor NASA have done that. Instead they point at the NASA design, say it's not as good as JUS, NASA are the experts, so JUS is not possible. That's a logical fallacy.

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My main worry about the JUS is thus: we all know that Ares-V is being pushed to greater performance (six engines, bigger SRBs, composites, etc). If a significantly better EDS is possible, why haven't NASA adopted such a design?

Good question to which the answer comes in several parts:1) EDS and JUS are not designed to perform exactly the same tasks.The environments & loads are somewhat different requiring different designs.2) JUS is bigger which in itself leads to greater mass efficiency.3) LM have much more experience with cryogenic upper stages, so you would expect their design to be more efficient.4) NASA have not asked for outside help with EDS. They want to develop the design experience in-house.

None of these alone account for all the differences, but add them all up...

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Other than the EDS, my main worry for DIRECT is the cost numbers. How do you buy a much larger tank, PLF, and thrust structure, an RS68, an SRB nozzle and recovery system, and three SRB segments, for only $15m?*

It's all very well cutting DIRECT some slack in this forum. But don't expect NASA to play that nicely. We need the proposal to be as tough as nails to stand up to whatever NASA can throw at it.

* this number assumes that Ares-I's J2X costs $25m and an RS68 is only $20m.

Existing 4-seg SRB & RS-68 costs are fairly fixed. About $80m per J-120 stack. $100m per J-232. Ares I and V SRB's and engines will be too, but at a higher rate for the RSB's because they will be 2 new designs with smaller production runs.

The big difference will be in the cost of building the Jupiter core & JUS vs ARES I US, Ares V core & EDS.

IIRC for 2 x ISS, 2 x Lunar Manned, 2 x Lunar Cargo you will need:

10 x Jupiter core, 8 x JUS VS 4 x AUS, 4 x Ares V core, 4 x EDS

Many of the production costs are fixed, so if you make more copies of a stage, EACH ONE WILL COST LESS. Conversely, making only a few of each, drives up the individual cost.

However, it would take the Direct team to provide me with an exclusive run on such news, because the other key element of this site is we never run second hand content.

Am I mis-reading this? ? ? ? You really won't report this unless DIRECT gives you an exclusive and refuses to talk to the rest of the press or any other news site? ? ? ? Hard not to understand your comment as meaning exactly this. Jeez.

I can understand if you need to hear directly from the source before you publish, but to say you won't list a news item just because someone else scooped you by 10 minutes is simply petty. It's still news (and directly from the souce), it's just not an exclusive.

I need to subscribe to some other news sites, I think, to hear all the news that you refuse to publish because someone beat you to it.

Martin

PS I'm very strongly tempted to apologise for such a dismissive tone, but if you really refuse to publish news because someone beat you to it, then you're not a news site, you're just screaming "first!" out to the internet. I would love to apologise if I've misunderstood the comment that I've quoted above, or its context.

We cover NASA and current vehicles - we are not covering Direct's development (and no news media site is). You're seeing numerous news media taking up a feature on Direct and that's cool - we've done the same back in 2006 and we've got the forum threads (also cool). No one is "missing" anything due to the update threads.

The clue is there in the NSF name. Loving the forum.

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It was intimated why we had not run another article on Direct based on (a) The latest magazine feature. Reason: not a viable news story for us to run with for the reasons given in my other post,

Yeah, just what I need - another news feed rehashing the same thing yet again.

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and (b) That we might pending any big news that directly (pun intended) relates to NASA's CxP direction.

I noted (b) would be viable if we get the news off the Direct team. Reason: It is unviable as a news site to rehash something already reported by another site. Some sites do re-write previously run content (with the "according to a report in the Blah Blah news...", but not us - we break news here for the reasons given of bringing something new to the party. But we still would run something if we had an additional angle. Basically, it HAS to be fresh news. No one here wants to re-read something they already know, and rightly so.

"Exclusive run" means breaking the news, it does not mean "do not to speak to another site." They are under no obligation to come to me with a breaking development, but the point is if they did, then I would run it (which answers the orginal question).

You've given excellent support, and I hope you get your scoop (assuming it's on-topic, of course). This forum has done a lot to get DIRECT's ideas out there and they've said more than once that your moderation has been important to this.

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So the bottom line is "yes" I would write a news article about Direct (I believe the intimation is I'm avoiding such content), but "no" I wouldn't write an article on news already reported, as the readership of this site expects me to give them something new in the articles.

The big difference will be in the cost of building the Jupiter core & JUS vs ARES I US, Ares V core & EDS.

IIRC for 2 x ISS, 2 x Lunar Manned, 2 x Lunar Cargo you will need:

10 x Jupiter core, 8 x JUS VS 4 x AUS, 4 x Ares V core, 4 x EDS

Many of the production costs are fixed, so if you make more copies of a stage, EACH ONE WILL COST LESS. Conversely, making only a few of each, drives up the individual cost.

Well, what we're really seeing here is the advantages of a common core stage between the J-120 and J-232. Think about it:

1) All your flights use the same core rather than having two separate designs.

2) The design keeps most of the external fuel tank, so you can use current facilities to produce the Jupiter core with minimal retooling, as opposed to making massive changes to your equipment to accommodate a new, larger design for Ares V or a new, smaller design for Ares I.

These two things alone would result in massive cost reductions when going with Jupiter. However, we can extend this out to the actual preparation and launch. Experience with prepping the J-120 in the VAB would be transferable to the J-232. You can't say the same for the Ares I and V, because they have different VAB platforms, crawlers, launch pads, et cetera. Once the Ares V rolls out, you'd practically need to retrain everyone who was working on the Ares I to work on the Ares V. However, with the J-232, you pretty much just train them on the upper stage and you're done. Not to mention the fact that NASA already has people who know how to put standard SRBs on something derived from the shuttle external fuel tank.

I just don't understand what's so mysterious about the Direct 2.0 numbers. It seems like people are just fishing for a problem. Everything is derivative on the Jupiter:

* Core fuel tank is the Shuttle ET.* Engines are from the Delta IV.* SRBs aren't even derivative, they're the SRBs.* Upper stage is a resized Atlas Centaur.* J2-X is a modified J2.

Direct 2.0 does have the burden of explaining the numbers and reasoning, but I find the level of skepticism a bit excessive.